SB SAT @ AMSAT $ANS-202.01
Presidents Letter July 2002
AMSAT News Service Bulletin 202.01 From AMSAT HQ
SILVER SPRING, MD. JULY 21, 2002
To All RADIO AMATEURS
BID: $ANS-202.01
Volunteers, AO-7 and other matters.
Recently there has been much discussion on the AMSAT-BB concerning the "Role
of Volunteers" in AMSAT-NA. Well let me say that AMSAT-NA is consists almost
entirely of volunteers. I am a volunteer, all the Board of Directors are
volunteers, and almost all of our Officers are volunteers.
However we do keep asking for more volunteers, when we don't always use the
ones that reply!
Why?
Very simply we need to have a pool of volunteers who are interested and
available so that when a "Situation Vacant" occurs we can get it filled
quickly. This particularly applies to designers and builders, who are
generally very
specialized in their areas of expertise.
Currently we have a shortage of Editors for ANS - we need two more - but we
have recently filled two positions very quickly. In the next few months we
will probably need some satellite builder expertise - but right now we need
names and background information so we can put the right people to work at
the
right jobs when the time arises.
Also I need some people who would like to be considered as future Presidents
of AMSAT-NA, do you have a background which would enable you to lead this
organization?. If so let me know. The training is good, but the pay is ....
well let me say Tax free and doubles every year .. if you know what that
means!.
The volunteer survey which was carried out earlier this year has enabled
AMSAT to select several "assistants" and other positions, please do not be
discouraged if you do not get an immediate answer to your volunteer request.
However as a recent AMSAT-BB E-mail said "Keep pushing" and let us know
you are there and ready to work!. The Volunteer survey is still available,
see the
AMSAT.org web page, about half way down on the right hand side click on
"Volunteer survey" to get a copy sent to you.
The re-discovery of AO-7 has raised many questions for satellite design,
particularly when it was apparent that one of the uplink frequencies is no
longer in the "Satellite part of the Spectrum". Of course AMSAT-NA is not a
regulatory body and it is not up to us to tell you what to do, or what not
to
do! that is up to your regulatory body in the country in which you transmit.
Please refer to them.
However AO-7 has raised a number of technical problems for future design.
Some of which are,
a) should we be able to remove the batteries from the circuitry at the end
of their life and keep the satellite operational on the solar cells only?
b) If so, with a multi-mode satellite how are we able to control the modes?
OR
c) At the end of battery life do we close the satellite down and return it
to earth?
All these questions are tied in with future possible regulations which may
require that "orbital debris" be returned to earth or burnt up in the
atmosphere on re-entry.
Certainly the experimentation of trying to control AO-7 using operational
codes will provide us with a great deal of knowledge and data for future
designs.
There are those who decry the attempts to control AO-7, but let us remember
that AMSAT's progress in satellite design and development has come about
from experimentation and knowledge, based on previous designs. There is
still a
lot we can learn from AO-7 and attempts to control it.
On a similar note using the RUDAK on AO-40 has taught us a great deal. It
has also provided some of AO-40 sponsors with much valuable information, and
may induce them to work with us again in the future. Yes, it is very
frustrating when
you cannot make a certain contact through the bird, because RUDAK is on
at the only possible time. But this will not always be the case, and that
valuable contact will eventually be made!
I understand from Martha, that the Ballots for the Board of Directors have
now been mailed. Please fill out your ballot and return it promptly. There
are five candidates to fill three positions - make your ballot count. May
the best candidates win!
In the same mailing is the Registration Form for the Annual Meeting and
Space Symposium, to be held in Fort Worth. Of all the attributes that
attracted me to AMSAT, when I first Joined, was the Space Symposium. Truly a
wealth of knowledge which is made available for so little cost. Other
organizations charge several hundred dollars for this type and quality of
information.
I strongly recommend you to attend, and meet the experts!
Also in your package is a President's Club membership form. Are you a
President's club member? do you support the design, building and launching
of our satellites?. Remember without satellites that satellite rig you have
may eventually become far less useful!.
Join the President's Club and make sure that by your regular contributions,
your satellite radio equipment remains useful. If you are already a member
paying yearly then now is a good time to renew and I look forward to hearing
that you are maintaining your support.
Enjoy your summer and have a great vacation
73
Robin Haighton VE3FRH
President AMSAT-NA \
/EX
SB SAT @ AMSAT $ANS-202.02
PCSAT DOWNLINK FREQUENCIES
AMSAT News Service Bulletin 202.02 From AMSAT HQ
SILVER SPRING, MD. JULY 21, 2002
To All RADIO AMATEURS
BID: $ANS-202.02
Many APRS operators may see DX stations as far as 2000 miles away pop up
on their local APRS RF area maps every now and then. These are received
from PCsat.
PCsat is currently relaying most APRS Satellite uplinks back down on both
145.825 AND 144.39. So anyone who's maps are not cluttered by all the
Internet feeds, might enjoy watching for PCsat DX a few times a day on
their normal terrestrial system.
Whenever PCsat resets (it does every 1.6 hours now when it goes into
dark), it cross connects the transmitters. Thus anyone uplinking on the
normal PCsat uplink of 145.825 will come down on BOTH unless a SYSOP
commands PCsat to isolate the transmitters.
Anyone with special needs can ask for access to the unpublished uplink
(contact wb4apr@amsat.org) to always come down on 144.39. Currently we
have one user, on a railroad car that uplinks so that he comes down on
144.39. Look for N3IYI.
More information is on the PCsat WEB page:
http://www.ew.usna.edu/~bruninga/pcsat.html
[ANS thanks Bob Bruninga, WB4APR, for the above information.]
/EX
SB SAT @ AMSAT $ANS-202.03
PCSAT MODE CHANGE TO DIGI OFF
AMSAT News Service Bulletin 202.03 From AMSAT HQ
SILVER SPRING, MD. JULY 21, 2002
To All RADIO AMATEURS
BID: $ANS-202.03
Bob Bruninga WB4APR announced that PCSat has turned DIGI OFF and all
1200 baud TLM off.
Although PCsat has been perfectly usable in the afternoons into early
evenings, the satellite is still running the batteries down on every
eclipse. So today I thought of one last low power mode I can try so
we turned DIGI and TELEMETRY OFF to see if we can make it through just
ONE eclipse. That's all we would need to recover PCsat back into a
positive power budget.
I will try this for the daytime passes over the USA this week (which
will affect the evening passes over Europe).
The lowest power mode of PCsat has been with all BULLETINS and all
DIGIpeating turned off. Also we disable 9600 baud 1 minute telemetry as
well. Thus the only thing remaining was the once per minute single 1200
baud telemetry packet which is required to keep the heart-beat fail-safe
reset timer tickled. What's new, is that we realized that if we switched
the 1/min TLM to 9600 baud instead of 1200, we would further reduce the
minimum transmit duty cycle in our lowest power mode. Thus halving our
transmit current drain.
Unfortunately, our TRANSMIT power is already less than 10% of the overall
bus power, so this move will only gain us about 5%, but worth trying...
Our minimum transmit average current drain (1 packet per minute) is
only about 16 ma out of the nominal 160 ma low power mode. Dropping this
in half saves us about 8 ma. Who knows, maybe it is the straw that can
give new life to the camel?
Anyway, when PCsat is in this minimum mode, the ONLY thing you will hear
will be a once a minute half second noise burst (9600 bd TLM) and nothing
else.
Sorry for the inconvenience. If you were planning a PCsat demo this week,
let us know and we will turn it back on. (WB4APR@amsat.org)
PCsat WEB page http://www.ew.usna.edu/~bruninga/pcsat.html
ISS-APRS FAQ: http://www.ew.usna.edu/~bruninga/iss-faq.html
CUBESAT Designs http://www.ew.usna.edu/~bruninga/cubesat.html
APRS LIVE pages http://www.ew.usna.edu/~bruninga/aprs.html
APRS SATELLITES http://www.ew.usna.edu/~bruninga/astars.html
[ANS thanks Bob Bruninga, WB4APR, for the above information.]
/EX
SB SAT @ AMSAT $ANS-202.04
AO-7 COMMAND SUCCESS
AMSAT New Service Bulletin 202.04 From AMSAT HQ
SILVER SPRING, MD. JULY 21, 2002
To All RADIO AMATEURS
BID: $ANS-202.04
I guess it's time for me to step forward out of the shadows. The behavior
you're observing is being caused by me, N1JEZ. I'm the so called "Covert
AO-7 Command Operator".
Before everyone gets all crazy, please let me try and explain a few things.
First, I asked to remain "covert" for a period of time because I did
not want to have to deal with the inevitable flood of email that will
result from my identity being known. At the time, I was in a critical
phase of trying to command the bird and needed to concentrate on that
task. There were a number of technical hurdles to overcome, not the
least of which is dealing with 30 year old stuff.
I know I'm going to get a lot of email, so I've put together the following
FAQ. Please read through it. Hopefully it will answer some of your
questions and avoid you sending them to me.
=====
AO-7 FAQ
Q: Tell me how the commands work.
A: Sorry, I _will not_ discuss any of the command details. Don't even ask.
Q: Tell me how the hardware works.
A: Sorry, I _will not_ discuss any of the command details. Don't even ask.
Q: What are the plans for AO-7.
A: I haven't foggiest! My job is to investigate what commands work and
what commands don't after 21 years. It's really exciting, but tedious work.
Imagine the thrill of seeing this antique accept your first command after
all these years! For me, this is similar to the experience I had not long
ago hearing the AO-40 24 GHz K Band beacon the first time. I've gone from
techno to retro in a short period of time.
Q: I'm doing a satellite demo next Monday night. Can you make sure AO-7
is in Mode B?
A: Sorry, as I stated above, my only job is to test various commands.
Q: When it comes to AO-7. I'm mad as hell and I'm not going to take it
anymore! Just leave it alone!
A: OK, take one of your little yellow pills and then send off a note to
your favorite AMSAT official. Honestly, if you have concerns, voice them
to Robin, VE3FRH or one of the Board of Directors. Everyone here is trying
to do the right thing.
Q: How can I help?
A: Of most interest to me is how AO-7 "wakes up" as it enters sunlight.
Also, any observations of simultaneous multiple modes would be most
valuable. Yoshi Imaishi, JF6BCC is compiling an excellent list of
observations. Please send him whatever you have. jf6bcc@jarl.com
You can view the list at:
http://plaza16.mbn.or.jp/~palau/temp/AO7-mode-report.xls
Q: Can you tell us _anything_ about this satellite?
A: I can tell you that command attempts are successful. I've only tested
a very limited number of functions, but it's very encouraging. I hope
to be able to do a write up on all the fun I've been having. Maybe it
will be in the AMSAT Journal or perhaps a presentation at the
AMSAT Symposium later this year. (get your tickets now )
=====
I still have a ton of work to do. So please try and keep the email to
a minimum. I'll try and answer what I can.
[ANS thanks Mike Seguin, N1JEZ, for the above information.]
/EX
SB SAT @ AMSAT $ANS-202.05
AO-40 UPDATE
AMSAT News Service Bulletin 202.05 From AMSAT HQ
SILVER SPRING, MD. JULY 21, 2002
To All RADIO AMATEURS
BID: $ANS-202.05
The K-Tx sessions have been discontinued due to increasing solar
angle. We will post more detailed plans for the upcoming bad solar
alignment shortly. The proposal currently under study is to move ALON
forward ahead of the sun in several increments to approximately ALON =
45. When the sun approaches 45 degs at this position, we will "duck" ALAT
to provide adequate power, slow spin to maximize mystery effect (ME) and
let the ME drift us around to approximately ALON = 315 where we should
re-acquire sensors and be able to return ALAT to 0. We can then follow
the sun back towards 0/0 over the following ~45 days. This approach should
minimize transponder "down" time to a few weeks, when the ALAT is not
optimal and we are drifting in ALON due to the mystery effect. Timing of
transponder and RUDAK windows, as before, will have to be shortened and
moved to provide optimum squint.
N QST AO-40 S2 Downlink #=Wednesday only 2002-07-16
MA 036 120# 128 160 200 240 036
---------1-----4-----3-----5-----7-----0-----1
MB | * | * | | * | * | * |
RUDAK | | | * | | | |
V-Rx | | * | * | | | * |
U-Rx | * | | | * | * | |
Passband | UL | VL | | UL2 | | |
M QST AMSAT OSCAR-40 2002 July 16
ALON/ALAT ~ 6/2
Shortly we will further increase ALON to move ahead of the sun.
*** See N-block for schedule.***
*** Middle Beacon OFF during RUDAK ***
The AO-40 team would like your telemetry files!
Please "zip" compress your daily telemetry files and e-mail to:
ao40-archive@amsat.org
[ANS thanks Stacey Mills, W4SM, for the above information.]
/EX
SB SAT @ AMSAT $ANS-202.06
OSCAR-11 REPORT
AMSAT News Service Bulletin 202.06 From AMSAT HQ
SILVER SPRING, MD. JULY 21, 2002
To All RADIO AMATEURS
BID: $ANS-202.06
OSCAR-11 REPORT 16 July 2002
After the problems reported last month, the satellite has returned to
normal operation. During the period 14 June to 15 July 2002
reception of the 145.826 MHz. beacon has varied between good and
poor. At times there has been packet QRM and splatter from other
users on the channel, and I have also experienced some local QRN.
These problems have masked any possible effects of the low battery
voltages.
The internal temperatures decreased by one degree C at the start of
the period. For the last three weeks they have been very stable and
are now -0.8 C and -1.8C for battery and telemetry electronics
respectively. Some increase in temperatures is expected in the next
few months, but this increase always tends to be later than expected,
from the eclipse predictions.
The battery voltage observed during daylight passes has decreased
slightly. The average value observed was 12.8 with a range of 12.2
to 13.6 volts.
The spin period has varied between -349 and -527 seconds, with no
particular trend observed. The value of 363 has occurred an unexpected
number of times. There have been 316 Z axis, three plus spin, and
316 negative spin magnetorquer firings during this reporting period.
The SEU count rate has continued to remain stable at 1150 counts per
day. Decoding the SEU binary telemetry shows six memory locations
39C0, 21C0 3EC0, 37B1, 180 and F96 have failed. These permanent
memory failures tend to mask out the display of the less frequent
failures, owing to the limited storage for this data in the
satellite. A program for decoding the SEU packets (U2PKT.ZIP) may be
downloaded from my website. URL details below.
The WOD survey of channels 1, 2, 3, 61 (X, Z, Y magnetometers and
status) dated 22 May 2002 has been transmitted. This survey shows
an unusually long spin period of 1800 seconds. This WOD may now be
downloaded from my web site, details below.
The mode-S beacon on 2401.5 MHz. has been heard by Christian F1AFZ,
and Roy VE7BPB. Christian reported strong signals, and has sent a
spectrogram which clearly shows two carriers separated by 1200 Hz.,
ie. the modulation frequency. Roy reports signals S2 above noise, and
has also heard a second carrier. He is using an 86 cm dish, with a
K3TZ patch feed, and an AIDC 3731 converter. Many thanks for those
reports.
I have also managed to hear the mode-S beacon, using a 60Cm offset
dish with 5 turn helix feed, AIDC 3731 converter, and FT726 receiver.
Signals were weak, just moving the S-meter above the noise. I
positioned the dish in the garden for 20 degree elevation during the
first part of the pass, and then repositioned in azimuth for the end
of the pass, at the same elevation. I managed to hear signals from
both directions. Beginners luck, I guess, as it was my first attempt
to hear this beacon!
The operating schedule is unchanged.
ASCII status (210 seconds)
ASCII bulletin (60 seconds)
BINARY SEU (30 seconds)
ASCII TLM (90 seconds)
ASCII WOD (120 seconds)
ASCII bulletin (60 seconds)
BINARY ENG (30 seconds)
The ASCII bulletin (number 115) is currently a static message,
detailing modes and frequencies of some of the older amateur radio
satellites.
There are additional status blocks after each bulletin is
transmitted, and between ASCII TLM and WOD.
The mode-S beacon is ON, nominally transmitting an unmodulated
carrier on 2401.5 MHz. There is however a VERY low level of AFSK
modulation which has been detected on strong signals. Telemetry
indicates that the beacon has partially failed, and is delivering
half power. This beacon is a useful test source for those testing
mode-S converters, as an alternative to OSCAR-40. However the signals
are very weak, and there is a lot of Doppler. Users should also note
that the polarization of OSCAR-11 is LHC. Even if you can't hear
OSCAR-11, your equipment may still be OK for OSCAR-40. Any reports
of reception on 2401.5 MHz. would be most welcome. Please e-mail
g3cwv@amsat.org.
The 435.025 MHz. beacon is normally OFF. However it can sometimes be
heard when the satellite is being commanded by ground control, ie.
within range of Guildford, UK. When the 435 beacon is transmitting,
the 145 beacon is normally OFF. The data transmitted is mainly
binary.
Listeners to OSCAR-11 may be interested in visiting my web site. The
web site contains details of hardware required and some software for
capturing data, and decoding ASCII telemetry and WOD. There is an
archive of raw data (mainly WOD) for analysis, which is continually
being expanded, as new data is captured. Also included are some
audio files, examples of each type of data transmitted by OSCAR-11,
each one plays for about ten seconds. There are also examples of
mode-S reception. All the audio files are zipped, so that they can
be played off-line. These should help listeners identify the various
types of data, and give an indication of the signal quality required
for successful decoding.
The URL is -
http://www.users.zetnet.co.uk/clivew/
If you place this bulletin on a terrestrial packet network, please
use the bulletin identifier $BID:U2RPT74.CWV, to prevent duplication.
73 Clive G3CWV g3cwv@amsat.org
[ANS thanks Clive Wallis, G3CWV, for the above information]
/EX
SB SAT @ AMSAT $ANS-202.07
SATELLITE BEGINNERS NET ANNOUNCEMENT
AMSAT News Service Bulletin 202.07 From AMSAT HQ
SILVER SPRING, MD. JULY 21, 2002
To All RADIO AMATEURS
BID: $ANS-202.07
Neil W6FOG has announced a new net for satellite beginners. The first
session of the net was held on Wednesday, July 17, 2002 starting at 1900
hours PDT (0200 UTC). The net will continue to meet on following Wed-
nesdays at this same time.
The first half hour from 7 PM PDT (0200 UTC) TO 730 PM PDT (0230 UTC) will
be for the first time users to get people's feet wet on working FM
satellites.
The 7:30 to 8:00 time slot will focus on training for working all the
satellites, what it takes, antennas, radio's, tracking programs, and do it
your self construction.
8:00 to 8:30 PM is the Question and Answer session.
All of the net details, including the check-in procedure are on-line at:
http://www.w6fog.net .
[now http://www.w6fog.com as of September 29, 2002]
[ANS thanks Neil, W6FOG, for the above information.]
/EX
SB SAT @ AMSAT $ANS-202.08
NEWS IN BRIEF FOR THIS WEEK
AMSAT News Service Bulletin 202.08 From AMSAT HQ
SILVER SPRING, MD. JULY 21, 2002
To All RADIO AMATEURS
BID: $ANS-202.08
** The US space agency NASA expressed optimism Friday that it will be able
to resume space shuttle flights in September once it has resolved the
mystery surrounding a series of small cracks found in the metal fuel liners.
--SpaceDaily
** A giant leap toward enabling high power electric propulsion was
recently demonstrated. With power levels up to 72 kW and nearly
3 Newtons of thrust, NASA's Glenn Research Center, Cleveland,
has designed, built and successfully tested a 50 kW-class Hall thruster.
--SpaceDaily
** A Russian nuclear submarine on Friday, July 12, successfully launched a
unique mini-space shuttle capable of delivering cargo to the International
Space Station (ISS) and safely returning to earth, officials said.
--SpaceDaily
** Congrats go out to Kenneth Ransom, N5VHO, for earning AMSAT OSCAR
Satellite Communications Achievement Award #353. For information on
the AMSAT awards visit http://www.amsat.org or
http://www.amsatnet.com/awards.html --Bruce KK5DO
** After a year-long study, a National Research Council panel has concluded
that sending a spacecraft to several bodies in the Kuiper Belt, including
Pluto, should be NASA's highest solar-system priority in the coming
decade. The study, also endorses a Europa Geophysical Explorer (EGE)
mission to place a craft in orbit around Jupiter's enigmatic icy moon
Europa. -- (Copyright) Used by permission Sky &Telescope Weekly News
Bulletin http://SkyandTelescope.com/news/
** On 11 July 2002, Europe took a step closer to Venus. The ESA Science
Programme Committee agreed unanimously to start work on Venus Express. Venus
Express will reuse the Mars Express spacecraft design and needs to be ready
for launch in 2005. --SpaceDaily
** If you are interested in joining the on-line satellite discussion in
the #amsat channel on IRC follow the directions at this link:
http://www.amsatnet.com/irc.html --Bruce KK5DO
/EX